Process for the preparation of bis-triazolylstilbenes

Abstract

Process for the preparation of bis-triazolylstilbene compounds which, in the form of the free acid, correspond to the formula ##STR1## wherein the phenyl radicals A can be substituted by halogen, C 1 -C 4 -alkyl or C 1 -C 4 -alkoxy, from bis-hydroxyiminohydrazonostilbene compounds of the formula ##STR2## characterized in that the bis-hyroxyiminohydrazonostilbene compounds are reacted with anhydrides of lower carboxylic acids in the presence of urea and polar solvents at temperatures from 10° to 60° C.

We claim: 
     
       1. In the reaction of a bis-hydroxyiminohydrazonostilbene compound of the formula ##STR5## wherein the phenyl radicals A can be substituted by halogen, C 1  -C 4  -alkyl or C 1  -C 4  -alkoxy, with a cyclizing agent to produce the corresponding bis-triazolylstilbene compound of the formula ##STR6## the improvement wherein the cyclizing agent is a lower carboxylic acid anhydride and the reaction is effected in the presence of urea and a polar solvent at from 10° to 60° C.   
     
     
       2. A process according to claim 1, wherein the temperature is from 25° to 45° C.